1. Field of the Invention
The invention relates to electronic device packages, and more particularly to image sensor packages with electromagnetic compatibility (EMC) coating thereon.
2. Description of the Related Art
Anti-electromagnetic interference (EMI)/electromagnetic compatibility (EMC) are essential to digital cameras utilizing high-resolution electronic imaging sensors. Metal cases are conventionally used as EMC means to prevent electromagnetic interference from other components in the digital camera system. Although metal cases have some mechanical advantages, they occupy a lot of space. Moreover, reworking or reprocessing image sensor modules with metal cases when required, such as when misassembled, is difficult, thus resulting in higher production costs and lower yields.
U.S. Pub. No. 2003/0223008, the entirety of which is hereby incorporated by reference, discloses a camera module which consists of an image sensor module assembled with an image signal process package on a substrate. An EMC layer is encapsulated on the back side of the substrate.
FIG. 1 shows a schematic view of a conventional metal case assembled with an image sensor module. Referring to FIG. 1, an optoelectronic package 10 includes a metal case 9 assembled with an image sensor module. The image sensor module is composed of an image sensor chip scale package (CSP) 3, a cover glass 5 on the CSP 3, and a set of optical lenses 7 with an aperture 6. Note that making the metal case 9 conform to the image sensor module is difficult. Practically, the metal case assembly is soldered and mounted on a printed circuit board (not shown), wherein the printed circuit board is externally connected to the ground. Additional assemble procedures are needed, which increases production costs. The optoelectronic package 10 configured with the metal case can only be tested after a backend process of being grounded to the printed circuit board is completed. As a result, when errors are found during anti-EMI capability testing, reworking or reprocessing the image sensor modules is difficult. Therefore, an EMC shield capable of preventing package assembly errors as well as reducing inner EM scattering interference effects is desired.